Stop motion switch for controlling thread tension in a textile machine

ABSTRACT

An electromechanical stop motion device for use with a testile machine, including a casing and a pair of relatively movable contacts mounted in the casing and adapted when closed to complete both an operating circuit for stopping the textile machine and the supply circuit of an externally visible indicating lamp. A shaft mounted in the casing supports an angularly movable thread feeler located externally of the casing. Also mounted in the casing is circuitry which is connected to electrical connector contacts projecting externally from the casing and to the indicating lamp as well as to the relatively movable contacts. Two parallel shafts are mounted in the casing, one of which is adjustable to vary the distance of the axis of a tension spring, which spring forms part of an over-center device operatively connected to a tension-sensing thread support arm, from the center point through which the spring axis passes when the over-center device is in a condition of unstable equilibrium. The other shaft is adjustable to vary the tension of the spring.

United States Patent [1 Quellos Feb. 18,1975

[ STOP Mo o SWITCH Eon CONTROLLING THREAD TENSION IN A TEXTILE MACHINE [76] Inventor: Antonio Sala Quellos, Lepanto Street No. 56, Mataro, Spain [22] Filed: Dec. 14, 1973 [21] Appl. No.: 424,788

[30] Foreign Application Priority Data [58] Field of Search 200/5 R, 5 A, 61.13, 61.18, 200/166 PC, 292; 66/161, 163; 19/25, .26; 139/353, 354

[56] References Cited UNITED STATES PATENTS 2,964,986 12/1960 Johnson 200/5 A X 3,789,631 2/1974 Deniega ZOO/61,18 X 3,806,677 4/1974 Deniega et a1. ZOO/61.18 X

ll (I Primary Examiner-James R. Scott Attorney, Agent, or Firm-Woodhams, Blanchard and Flynn [57] ABSTRACT An electromechanical stop motion device for use with a testile machine, including a casing and a pair of relatively movable contacts mounted in the casing and adapted when closed to complete both an operating circuit for stopping the textile machine and the supply circuit of an externally visible indicating lamp. A shaft mounted in the casing supports an angularly movable thread feeler located externally of the casing. Also mounted in the casing is circuitry which is connected to electrical connector contacts projecting externally from the casing and to the indicating lamp as well as to the relatively movable contacts. Two parallel shafts are mounted in the casing, one of which is adjustable to vary the distance of the axis of a tension spring, which spring forms part of an over-center device operatively connected to a tension-sensing thread support arm, from the center point through which the spring axis passes when the over-center device is in a condition of unstable equilibrium. The other shaft is adjustable to vary the tension of the spring.

10 Claims, 3 Drawing Figures STOP MOTION SWTICH FOR CONTROLLING THREAD TENSION IN A TEXTILE MACHINE The present invention relates to improvements in electromechanical stop motion devices for textile machines and is concerned with improvements in devices of this character which are designed to control excess tension or lack of thread due to faults in or breakdowns of the machines with which these devices are used.

The improvements include a lever which rests on a thread whose tension is to be adjusted. The lever slackens at a determined tension and as it moves it closes the machine stopping circuit and the circuit for the indicator light. The improvements have been provided with devices for regulating the tension and these devices include a mechanism which displaces the point of anchorage of the tensor spring. There are also devices for varying the alignment of the two points of anchorage of the spring at its ends so that the unstable point of equilibrium in the lever outside the release is established at different angular amplitudes.

According to this invention there is provided an electromechanical stop motion device for use with a textile machine, including a casing, a pair of relatively movable contacts mounted in said casing and adapted when closed to complete both an operating circuit for stopping the textile machine and the supply circuit of an externally visible indicating lamp and a shaft mounted in said casing and supporting an angularly movable thread feeler located externally of said casing, characterized by the fact that there are also mounted in said casing circuitry which is connected to electrical connector contacts projecting externally from said casing and to the indicating lamp as well as to the said relatively movable contacts, and two parallel shafts, one of which shafts is adjustable to vary the distance of the axis of a tension spring, which forms part of an over-center device operatively connected to a thread engaging arm, from the center point through which said spring axis passes when the over-center device is in a condition of unstable equilibrium, and the other of which shafts is adjustable to vary the tension of said tension spring.

An embodiment of this invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a front view of the electromechanical stop motion device according to an embodiment of the in vention,

FIG. 2 is a cross section of the device taken along the line ll-ll in FIG. 1 with certain parts removed for the sake of clarity, and

FIG. 3 is a fragmentary view similar to FIG. 1 and showing the tension lever and the feeler in their operative positions.

The stop motion device shown in the drawings has a small boxlike casing 1 within which are mounted a pair of contact arms 2, one of which is fixed and the other movable. The contacts carried by these contact arms 2 are connected, via circuit contacts 4A on a printed circuit board 4 housed in the casing l, to externally projecting flexible plug connector pins 5 which in turn can be connected to the control circuit ofa mechanism for stopping a textile machine (not shown) on which this stop motion device is fitted when the said contacts 2 are closed. These contacts are also connected, via the circuit 48 on the printed circuit board 4, with an indicator lamp 3 so that this lamp 3 will be illuminated when the said contacts are closed.

Rotatably mounted in the casing l are two parallel shafts 6 and 7. The shaft 6 is formed with a male screwthread 12 which engages with a corresponding female screw-thread in the bore of a pulley 14 mounted on the shaft 6. A control knob 13 fixed on an externally projecting end of the shaft 6 serves for rotating the latter and thereby displacing the pulley l4 axially along it. A core 15, which has one end connected to a recess or collar 16 on the shaft 6 and the other end connected at 17 to the upper end of a tension spring 8, passes over the pulley 14 which is formed with an annular groove for locating this cord. The lower end of the tension spring is connected to an anchorage pin 18 which projects axially from the lower part of one face of a counter-balance wheel 19, which wheel 19 is eccentrically fixedly secured on one end of a shaft portion 9 of a thread tensioning lever arm 10, which shaft supports thereon a tensioned thread T. The shaft portion 9 is rotatably mounted in a needle roller bearing comprising needle rollers 23 arranged within a fixed outer race member 22 mounted in a wall of the casing I. The

spring 8 normally maintains the arm 10 in its upper-.

most position, as shown by solid lines in FIG. I, wherein it engages the bottom wall of the casing l.

The casing 1 also supports an independently movable gravity-actuated feeler arm 20, which is adapted to rest on the travelling thread T entering or passing through the textile machine and is mounted for angular movement about the axis of a shaft portion 21. Rigidly but eccentrically secured on this shaft portion 21, which is rotatable in a bearing mounted on the casing I, is a cam 24 for closing the contacts 2. When the feeler arm 20 moves about the axis of the shaft portion 21, due to a thread breakage or an increase in the tension of the thread, it causes the eccentric cam 24 to rotate and press the movable contact arm 2 towards the fixed contact arm 2, thereby closing the circuit which effects the stopping of the textile machine.

The stop motion device can be adjusted to change the amount of alteration in thread tension that is necessary before the anchorage pin 18 will be moved past the position of unequal equilibrium in which a straight line joining the center of this pin 18 with a point in the groove of the pulley 14 located on the right hand side thereof as seen in FIG. 2 and level with the axis of the shaft 6 passes through an extension of the axis of the shaft portion 9. To achieve this the knob 13 is turned so as to displace the pulley 14 a suitable distance along the shaft 6 thereby varying the angular extent through which arm 10 must be moved prior to passing through the unstable center portion. In addition, the tension of the spring 8 can be adjusted as required by turning the knob 11 fixed on the shaft 7, which causes the cable 15 to be wound up on the collar 16.

The horizontal portions of the arms 10 and 20, as illustrated in FIG. 3, are each of a substantially U-shaped configuration, with the horizontal portion of arm 20 being positioned within the horizontal portion of the arm 10.

The stop motion mechanism operates as follows:

During normal operation, the arm 10 is maintained in its upper position as shown in FIGS. 1 and 3. The tensioned thread T passes over the arm 10, which arm causes an upward deflection and a tensioning of the thread. The feeler 20, due to its own weight, rests on the upper surface of the thread as shown in FIG. 3.

When the thread T breaks, the feeler 20 swings downwardly about shaft 21 due to its own weight, thus causing cam 24 to engage and close the contacts 2 as shown in FIGv 1.

When the thread tension exceeds a preselected value, a determined by the adjustment of the spring 8, the thread swings the lever downwardly (clockwise in FIG. 1). When the lever 10 reaches its unstable center position, the spring 8 rapidly moves the lever I0 into the over-center release position illustrated by dotted lines in FIG. 1. During the downward swinging of the lever 10, the weight of feeler also causes it to swing downardly from its FIG 3 position to its FIG. 1 position whereby the cam 24 engages and closes the contacts 2.

The tension at which the thread causes movement of lever 10, as described above, can obviously be selectively varied by rotating the knob 13 to vary the tension of the spring 8.

Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangements of parts, lie within the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an electro-mechanical stop motion device for use with a textile machine for controlling the tension in a traveling thread, including a casing, a pair of relatively movable contacts mounted in said casing and adapted when closed to complete both an operating circuit for stopping the textile machine and a supply circuit of an externally visible indicating lamp, a shaft mounted on the casing and supporting an angularly movable gravity-actuated thread feeler located externally of the casing, said thread feeler being operatively connected to the contacts for controlling the position thereof and being normally maintained in an uppermost position when supported on the thread wherein said contacts are opened, a thread tensioning arm swingably supported on said casing and movable between a first position for engaging said tensioning the thread and a second position for releasing the tension on the threads, and an over-center spring device mounted on said casing and connected to said thread tensioning arm for normally maintaining said arm in either of said first or second positions, movement of said arm between said first and second positions causing same to be moved about a center point through an intermediate unstable position, said over-center spring device including a tension spring which is subject to imposition of a maximum tension thereon when said device is in said intermediate unstable position, the improvement comprising:

printed circuit board means mounted in said casing and defining thereon circuitry means connected to said indicating lamp and said relatively movable contacts, said circuitry means also being connected to electrical connector contacts which project externally from said casing for controlling the stopping of the textile machine;

first means for adjusting the angular extent through which said thread tension arm must be moved in moving between said first portion and said intermediate unstable position, said first means including a first shaft movably supported on said casing and means interconnecting said shaft to said tension spring for shifting said spring relatively to said center point; and

second means for adjusting the tension in said tension spring, said second means including a second shaft movably supported on said casing and means interconnecting said shaft to said tension spring, said second shaft being disposed substantially parallel to said first shaft.

2. A device according to claim 1, wherein said first and second shafts are each rotatably supported on said casing, and first and second manually engageable knobs respectively mounted on said first and second shafts and positioned externally of said casing for permitting selective manual rotation of said shafts.

3. A device according to claim 1, wherein said overcenter device includes cable means having one end thereof anchored to said second shaft and the other end thereof anchored to one end of said spring, whereby rotation of said second shaft causes said cable means to be wound thereon or unwound therefrom for adjusting the tension of said spring, and said first means including a cable-engaging portion associated with said first shaft and shiftable axially of said first shaft, said cableengaging portion being maintained in engagement with an intermediate portion of said cable means, whereby axial shifting of said cable-engaging portion shifts the axis of said spring relative to said center point.

4. A device according to claim 3, whereby said first shaft is rotatably supported on said casing and is disposed in screwthreaded engagement with said cableengaging portion for causing axial shifting movement of said cable-engaging portion upon rotation of said first shaft, said cable-engaging portion comprising a pulley having a circumferential groove formed therein for receiving therein the intermediate portion of said cable means.

5. In a threaded tension control device for controlling the tension in a traveling thread associated with a textile machine, said device including a casing and thread tension sensing means adapted to support said traveling thread, said sensing means including a thread engaging arm pivotally mounted on said casing for swinging movement about a pivot axis, said arm being swingable between a first position wherein it engages the thread for tensioning same and a second position which is angularly spaced from said first position for releasing the tension in said thread;

an over-center spring device operatively connected at one end thereof to said arm for normally maintaining same in either said first or second position, said over-center spring device having one end thereof connected to said arm at a location spaced radially from said pivot axis whereby said spring device assumes an unstable central position when said arm is moved into an unstable third position which is located intermediate said first and second positions, said over-center spring device including spring means which defines a biasing force axis which intersects said pivot axis when said spring device is in said unstable central position; and first means for selectively adjusting the spring biasing force associated with the spring of said over-center device for correspondingly selecting the predetermined thread tension which will cause movement of said arm away from said first position;

the improvement comprising second means for selectively adjusting the spacing of said biasing axis of the over-center spring device from said pivot axis to vary the angular extent through which said arm must be swingably moved in being displaced between said first and third positions, said second means being independent of said first means.

6. A device according to claim 5, wherein said first and second means respectively include first and second manually engageable adjustment members positioned externally of said casing.

7. A device according to claim 6, wherein each of said first and second adjusting members are rotatable relative to said casing.

8. A device according to claim 5, wherein said first means includes a first shaft rotatably supported on said casing, and said over-center spring device including elongated flexible cable means connected between said first shaft and the other end of said spring, whereby rotation of said first shaft causes said flexible cable means to be wound or unwound from said shaft for adjusting the biasing force of said spring.

9. A device according to claim 8, wherein said second means incudes a second shaft rotatably supported on said casing and disposed substantially parallel to said first shaft, said second shaft having a cableengaging portion associated therewith and disposed in engagement with an intermediate portion of said cable means, said second means also including means coacting between said second shaft and said cable-engaging portion for causing said cable-engaging portion to be shifted axially relative to said second shaft upon rotation thereof for shifting the spring biasing axis relative to said pivot axis.

10. A device according to claim 5, wherein said second means includes a shaft rotatably supported on said casing and means connected between said shaft and said spring for shifting the biasing force axis relative to said pivot axis upon rotation of said shaft.

UMTED STATES PATENT OFFICE CERTiFiCATE OF CORRECTION PATEr a NO. 3 867 592 DATE February 18,, 1975 INVEEYORJS) Antonio Sala Quellos it is 'tn'sed that error appeats m the above-identified patent and that said Letters Patent PIE- i y 0 .ed as shown below:

In the title, after the word "Switch" insert --Device--.

Column 3, line #5; change the phrase "engaging said tensioning" to -engaging and tensioning--.

line 48; change the phrase "on the threads" to --on the thread-.

line 68; change "first portion" to --first position--.

Column 4, line 9; change "said shaft" to --said second shaft--.

line 41; change "threaded" to ---thread-.

Column 5, line 15; change "adjusting" to --adjustmen.t--.

Signed and sealed this 27th day of May 1975.

(SEAL) Attest:

C. MARSHALL DAN-N Commissioner of Patents RUTH C. I-IASON and Trademarks Attesting Officer UNiTED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATET NO. 3 867 592 BATH} February l8, 1975 INVENYORJfi) Antonio Sala Quellos ii: is ca'nfed that error appea's m the above-identified patent and that said Letters Patent are commief as ehown below:

In the title, after the word "Switch" insert ---Device--.

line #5; change the phrase "engaging said tensionto -engaging and tensioning-.

Column 3, ingll line 43; change the phrase "on the threads" to ---on the thread-.

line 68; change "first portion" to ---first position-.

Column 4, line 9; change "said shaft" to --said second shaft--.

line 41; change "threaded" to --thread.-.

Column 5, line 15; change "adjusting" to --adjustment-.

Signed and sealed this 27th day of May 1975.

SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents and Trademarks Attesting Officer 

1. In an electro-mechanical stop motion device for use with a textile machine for controlling the tension in a traveling thread, including a casing, a pair of relatively movable contacts mounted in said casing and adapted when closed to complete both an operating circuit for stopping the textile machine and a supply circuit of an externally visible indicating lamp, a shaft mounted on the casing and supporting an angularly movable gravity-actuated thread feeler located externally of the casing, said thread feeler being operatively connected to the contacts for controlling the position thereof and being normally maintained in an uppermost position when supported on the thread wherein said contacts are opened, a thread tensioning arm swingably supported on said casing and movable between a first position for engaging said tensioning the thread and a second position for releasing the tension on the threads, and an overcenter spring device mounted on said casing and connected to said thread tensioning arm for normally maintaining said arm in either of said first or second positions, movement of said arm between said first and second positions causing same to be moved about a center point through an intermediate unstable position, said over-center spring device including a tension spring which is subject to imposition of a maximum tension thereon when said device is in said intermediate unstable position, the improvement comprising: printed circuit board means mounted in said casing and defining thereon circuitry means connected to said indicating lamp and said relatively movable contacts, said circuitry means also being connected to electrical connector contacts which project externally from said casing for controlling the stopping of the textile machine; first means for adjusting the angular extent through which said thread tension arm must be moved in moving between said first portion and said intermediate unstable position, said first means including a first shaft movably supported on said casing and means interconnecting said shaft to said tension spring for shifting said spring relatively to said center point; and second means for adjusting the tension in sAid tension spring, said second means including a second shaft movably supported on said casing and means interconnecting said shaft to said tension spring, said second shaft being disposed substantially parallel to said first shaft.
 2. A device according to claim 1, wherein said first and second shafts are each rotatably supported on said casing, and first and second manually engageable knobs respectively mounted on said first and second shafts and positioned externally of said casing for permitting selective manual rotation of said shafts.
 3. A device according to claim 1, wherein said over-center device includes cable means having one end thereof anchored to said second shaft and the other end thereof anchored to one end of said spring, whereby rotation of said second shaft causes said cable means to be wound thereon or unwound therefrom for adjusting the tension of said spring, and said first means including a cable-engaging portion associated with said first shaft and shiftable axially of said first shaft, said cable-engaging portion being maintained in engagement with an intermediate portion of said cable means, whereby axial shifting of said cable-engaging portion shifts the axis of said spring relative to said center point.
 4. A device according to claim 3, whereby said first shaft is rotatably supported on said casing and is disposed in screwthreaded engagement with said cable-engaging portion for causing axial shifting movement of said cable-engaging portion upon rotation of said first shaft, said cable-engaging portion comprising a pulley having a circumferential groove formed therein for receiving therein the intermediate portion of said cable means.
 5. In a threaded tension control device for controlling the tension in a traveling thread associated with a textile machine, said device including a casing and thread tension sensing means adapted to support said traveling thread, said sensing means including a thread engaging arm pivotally mounted on said casing for swinging movement about a pivot axis, said arm being swingable between a first position wherein it engages the thread for tensioning same and a second position which is angularly spaced from said first position for releasing the tension in said thread; an over-center spring device operatively connected at one end thereof to said arm for normally maintaining same in either said first or second position, said over-center spring device having one end thereof connected to said arm at a location spaced radially from said pivot axis whereby said spring device assumes an unstable central position when said arm is moved into an unstable third position which is located intermediate said first and second positions, said over-center spring device including spring means which defines a biasing force axis which intersects said pivot axis when said spring device is in said unstable central position; and first means for selectively adjusting the spring biasing force associated with the spring of said over-center device for correspondingly selecting the predetermined thread tension which will cause movement of said arm away from said first position; the improvement comprising second means for selectively adjusting the spacing of said biasing axis of the over-center spring device from said pivot axis to vary the angular extent through which said arm must be swingably moved in being displaced between said first and third positions, said second means being independent of said first means.
 6. A device according to claim 5, wherein said first and second means respectively include first and second manually engageable adjustment members positioned externally of said casing.
 7. A device according to claim 6, wherein each of said first and second adjusting members are rotatable relative to said casing.
 8. A device according to claim 5, wherein said first means includes a first shaft rotatably supported on said casing, and said over-center spring device including elongated flexible cable means Connected between said first shaft and the other end of said spring, whereby rotation of said first shaft causes said flexible cable means to be wound or unwound from said shaft for adjusting the biasing force of said spring.
 9. A device according to claim 8, wherein said second means incudes a second shaft rotatably supported on said casing and disposed substantially parallel to said first shaft, said second shaft having a cable-engaging portion associated therewith and disposed in engagement with an intermediate portion of said cable means, said second means also including means coacting between said second shaft and said cable-engaging portion for causing said cable-engaging portion to be shifted axially relative to said second shaft upon rotation thereof for shifting the spring biasing axis relative to said pivot axis.
 10. A device according to claim 5, wherein said second means includes a shaft rotatably supported on said casing and means connected between said shaft and said spring for shifting the biasing force axis relative to said pivot axis upon rotation of said shaft. 